JP2000041177A - Imaging device - Google Patents

Abstract

(57) [Summary] [Problem] When there is a high-luminance object in a captured image, symptoms such as so-called overexposure and underexposure appear, and the iris and A
It was difficult to set the value of GC at an appropriate position. A brightness determination reference value is provided, a brightness control value immediately before designation is compared with a brightness determination reference value, and when it is determined that the brightness control value immediately before designation is bright, the brightness control value of the designated range is determined. Increase the overall brightness so that the brightness of the video signal is appropriate, and if it is determined to be dark, adjust the control value by adding the overall brightness at a certain rate to the brightness of the specified range according to the dark situation To adjust the brightness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an imaging device, and more particularly to an imaging device with a monitor.

[0002]

2. Description of the Related Art In general, a method of adjusting the brightness of a video camera with a monitor is to measure a luminance level of a measurement area fixed by a camera without a photographer's designation and to adjust the luminance level to a reference value. Specifies the subject on the monitor on the monitor,
There is also a way to adjust the brightness.

The former method will be described as a first conventional example with reference to FIGS. FIG. 8 is a block diagram of a portion related to brightness correction in a video camera with a monitor.

In FIG. 8, reference numeral 1 denotes a lens for capturing an image of a subject, 2 denotes an aperture for adjusting the amount of light (hereinafter referred to as an iris),
Reference numeral 3 denotes a CCD of an image sensor, 4 denotes a CDS / AGC circuit that performs sample hold and gain adjustment, 5 denotes a signal processing circuit, 9 denotes a brightness measurement circuit, and 7 denotes a microcomputer (hereinafter, referred to as a microcomputer) that controls the entire system. is there.

FIG. 9 shows an imaged screen.
A, B, C, D, and E indicate divided areas of the screen.

FIG. 10 is a flowchart showing a procedure of the brightness adjusting method. Hereinafter, an outline of the operation will be described.

[0008] In the block diagram of FIG. 8, the light Sig 1 having passed through the lens 1 and the aperture 2 is converted into an electric signal S 2 by the CCD 3, sample-holded and gain-adjusted by the CDS / AGC circuit 4, and then sent to the signal processing circuit 5. And the signal processing output 5 from the signal processing circuit 5 to the next stage circuit (not shown).
ig4.

The luminance signal Sig generated by the signal processing circuit 5
7 is input to the brightness measurement circuit 9 and the brightness is measured.

The brightness measuring circuit 9 divides a captured image into five areas from an area A to an area E as shown in FIG. 9 and obtains an average value of the brightness of each area.

The microcomputer 7 reads the measurement result Sig9 from the brightness measurement circuit 9, and weights the average value of the brightness of each of the areas A to E with a predetermined weight to obtain the overall brightness.

The microcomputer 7 determines a correction value from the obtained brightness, and sets the correction value as an iris control signal Sig10 and an AGC control signal Sig11, respectively.
The AGC value of the DS / AGC circuit 4 is controlled.

FIG. 10 shows a flowchart of the above operation procedure. Step S60 is a standby process for securing a processing time in the brightness measurement circuit 9.

After waiting for a predetermined time, the microcomputer 7 reads out the measurement result of the brightness measurement circuit 9 in step S61.

Here, the microcomputer 7 obtains the brightness of the screen by applying a predetermined weight to the measurement result.

For example, in the area division shown in FIG. 9, when the area C and the area E are each weighted by 30%, the area A is weighted by 10%, and the area B and the area D are weighted by 15%, the brightness becomes A × 0.
1 + B × 0.15 + C × 0.3 + D × 0.15 + E ×
0.3.

The brightness thus obtained is compared with a reference value REF in step S62. If the brightness is equal, the brightness adjustment is terminated. If the brightness is not equal, the brightness is adjusted in step S63. Is compared with the reference value REF.

In step S63, brightness> reference value REF
If so, it is determined that it is brighter than the predetermined value, and step S64, which is a process of lowering the brightness, is performed.

In step S64, it is determined whether the current AGC value is larger than the minimum value. If the current AGC value is larger than the minimum value, in step S65, the AGC value is set to reduce the brightness.
Decrease the value. If the minimum value is reached, the AGC value cannot be reduced any more, so that the iris is changed in the closing direction in step S66.

After that, the process returns to step S60 again to wait for the change of the video signal and to measure the brightness again.

If it is determined in step S63 that the brightness is smaller than the reference value REF, it is determined that the brightness is lower than the predetermined value, and the process of increasing the brightness is performed in step S67.

In step S67, it is determined whether or not the current iris is fully opened. If it is not fully opened, in step S68, the iris is opened to increase the brightness, and the iris is fully opened. If you have
Since the iris cannot be opened any more, step S
At 69, the brightness is increased by increasing the AGC value.

Thereafter, the process returns to step S60 again to wait for the change of the video signal and to measure the brightness again.

A series of these data changes are controlled so that they change little by little because abrupt changes will result in unsightly images.

Next, a method of designating a subject to be photographed on a monitor and adjusting the brightness thereof will be described as a second conventional example with reference to FIGS.

A video camera with a monitor employing this method has a touch panel capable of touch input on a monitor section.

FIG. 11 is a block diagram of a portion related to brightness correction in a video camera with a monitor. The same components as those in FIG. 8 are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 11, reference numeral 6 denotes a touch panel stacked on a monitor, 10 denotes a brightness measurement circuit capable of changing a measurement area, S6 denotes an area designation signal, and S5 denotes a touch panel output voltage.

FIG. 12 shows a screen displayed on the touch panel monitor. FIG. 13 is a flowchart showing a procedure of the brightness adjusting method. Hereinafter, an outline of the operation will be described.

The description of the same operation as that of the first conventional example will be omitted, and the touch panel will be described.

From the touch panel 6, X at the pressed position
The (horizontal) and Y (vertical) coordinates are the touch panel output voltage Si
The value is input to the microcomputer 7 as g5.

The microcomputer 7 reads the voltage Sig5 from the touch panel 6 and detects where on the screen is specified.

At this time, the point specified by the touch panel is only a point, but it is necessary to measure a certain range so as to obtain measurement accuracy. The horizontal / vertical measurement start position and measurement width or the measurement start position and end position corresponding to the designated position are output as the region designation signal Sig6.

In the brightness measuring circuit 10, the signal processing circuit 5
From the luminance signal Sig7 generated by
The brightness of the area designated by 6 is measured.

The microcomputer 7 calculates the brightness measurement result Sig12
, The iris 2 and the CDS / A are determined.
The AGC value of the GC circuit 4 is controlled.

FIG. 13 shows a flowchart of the above operation procedure. First, in step S70, it is determined whether or not there is a touch designation. If the touch has not been performed, the operation of correcting the brightness by the method described in the first conventional example is performed in step S71.

On the other hand, if it is determined that a touch has been made,
In step S72, the microcomputer 7 obtains XY coordinates from the input voltage Sig5 from the touch panel 6.

In step S73, a range for measuring brightness is determined from the obtained XY coordinates. In ST74, a measurement range in the brightness measurement circuit 10 is set.

The brightness measuring circuit 10 measures the brightness of a designated range in one field or one frame, and in step S75, performs standby processing to secure a time required for the measurement.

In step S76, after waiting for a predetermined time in the standby process, the brightness measurement circuit 10 outputs the result of brightness measurement to the microcomputer 7 as Sig12.

The brightness thus obtained is compared with a reference value REF in step S77. If the brightness is equal, the brightness adjustment is terminated. If the brightness is not equal, the brightness is determined in step S78. Is compared with the reference value REF.

In step S78, brightness> reference value REF
If it is, it is determined that it is brighter than the predetermined value, and step S79 which is a process of lowering the brightness is performed.

In step S79, it is determined whether or not the current AGC value is larger than the minimum value. If the current AGC value is larger than the minimum value, in step S80, the AGC value is set to lower the brightness.
Decrease the value.

If the value is the minimum value, the AGC value cannot be reduced any more. Therefore, in step S81, the iris 2 is changed in the closing direction.

Thereafter, the process returns to step S75 again to wait for a change in the video signal and then re-measure the brightness.

If it is determined in step S78 that the brightness is smaller than the reference value REF, it is determined that the brightness is lower than a predetermined value, and the process of increasing the brightness is performed in step S82.

In step S82, it is determined whether or not the current iris 2 is fully opened. If it is not fully opened, in step S83, the iris is opened to increase the brightness. If so, since the iris 2 cannot be opened any more, the brightness is increased by increasing the AGC value in step S84.

Thereafter, the process returns to step S75 again to measure the brightness after waiting for a change in the video signal.

[0048]

The first problem shown in FIG.
In the conventional example, since the range for measuring the brightness is fixed, when a high-luminance subject such as the sun enters near the center of the screen as shown in FIG. 9, the iris closes and the face of a person becomes black. Symptoms.

On the other hand, if an attempt is made to properly adjust the face of a person manually instead of by the automatic operation, there is a problem that bright portions such as the sun are saturated and fly white, which is a so-called overexposure phenomenon.

In the second conventional example shown in FIG.
Although the position where the brightness is to be adjusted can be specified, the iris opens to make that portion brighter, such as when the face of a black sunken person is specified in a backlight condition as shown in FIG. You will fly. Further, when the sun is specified, the iris closes, resulting in a very uncomfortable screen such as a person's face being further blackened.

[0051]

In order to solve the above problems, the present invention has the following arrangement. That is, the invention according to claim 1 is an image pickup apparatus having a monitor in which a touch panel is stacked on a screen, a brightness adjusting means for adjusting brightness of a video signal, a control means for controlling the brightness adjusting means,
Specifying means for specifying a specific portion in the video signal, first measuring means for measuring the brightness from the video signal of the portion specified by the specifying means, and from the video signal when not specified by the specifying means Measuring brightness, at least one or more second measuring means, and calculating means for calculating a control value of the brightness adjusting means based on the first measuring means output and the second measuring means output; Wherein the brightness of the video signal is adjusted by the control value of the arithmetic means. The invention according to claim 2, wherein the arithmetic means comprises:
A control value of the second measurement means output having at least one or more brightness determination reference values and comparing a control value by the output of the second measurement means immediately before designation with the brightness determination reference value; Is determined to be brighter, the brightness of the video signal is adjusted at the output of the first measuring means, and when it is determined to be dark, the first measurement is performed according to the degree of darkness. 2. The image pickup apparatus according to claim 1, wherein an operation of adding the output of the second measuring means to the output of the means at a specific ratio is performed. In an imaging device having a stacked monitor,
Brightness adjusting means for adjusting the brightness of the video signal, control means for controlling the brightness adjusting means, specifying means for specifying a specific portion in the video signal, and brightness measuring means for changing the measurement area; A gamma characteristic varying unit capable of varying a gamma characteristic; and a calculating unit for calculating a control value of the brightness adjusting unit based on the output of the measuring unit, and the brightness adjusting unit based on the output of the specifying unit. And controlling the gamma characteristic varying means to adjust the brightness of the video signal. The invention according to claim 4 is characterized in that when a user designates a position during shooting, 4. The image pickup apparatus according to claim 3, wherein a characteristic of the gamma characteristic variable unit is changed to a characteristic different from a characteristic when the position is not specified, and brightness adjustment control is performed. ,Claim The invention according to claim 5 is the imaging device according to any one of claims 1 to 4, wherein the designation unit capable of designating the specific portion in the video signal is a touch panel stacked on a monitor. .

[0052]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram of a portion related to brightness adjustment of the present embodiment. The same components as those in FIGS. 8 and 11 of the conventional example are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 1, reference numeral 8 denotes a first measurement circuit for measuring the brightness of a video signal in a designated portion, 9 denotes a second measurement circuit for measuring the brightness of a video signal over the entire area, and Sig8.
Is the first measurement circuit output, and Sig9 is the second measurement circuit output.

FIG. 2 is a flowchart for explaining the operation procedure of this embodiment. Hereinafter, the operation in the present embodiment will be described. The microcomputer 7 calculates the output voltage S of the touch panel 6
For the first measurement circuit 8 that can change the measurement position in accordance with the specified position detected from ig5, the measurement range such as the horizontal and vertical measurement start position and measurement width or the measurement start position and end position is specified by Sig6. I do.

In the first measuring circuit 8, the luminance signal Sig
7, the brightness of the measurement range specified by Sig6 is measured, and the measurement result is output to microcomputer 7 as Sig8.

At the same time, the second measuring circuit 9 for measuring the entire screen measures the brightness of the entire screen from the luminance signal S7 and outputs the measurement result to the microcomputer 7 as Sig9.

The microcomputer 7 calculates the brightness from the brightness measurement results Sig8 and Sig9, determines a correction value by comparing with a reference value, and uses the control signals of Sig10 and Sig11 to control the iris 2 and the CDS / AGC circuit 4, respectively. Control the AGC value of

Next, the procedure of the above operation will be described in detail with reference to the flowchart of FIG. In step S1, it is determined whether or not a position on the screen at which brightness is to be adjusted is designated.

Specifically, the XY input to the microcomputer 7
Is changed from the non-touched state to the touched state, and if the voltage is not touched, as step S2, an operation of correcting by the method described in the first conventional example is performed. On the other hand, if it is determined that the touch has been made, the microcomputer 7 obtains the XY coordinates from the input voltage Sig5 in step S3.

In step S4, a range for measuring brightness is determined from the obtained XY coordinates. Specifically, a certain width is set with the designated point as the center. At this time, if the area is small, the influence of noise increases, so a certain area is required.

In step S5, the microcomputer 7 sets the determined measurement range in the first measurement circuit 8.

The first brightness measurement circuit 8 and the second brightness measurement circuit 9 measure the brightness of a specified range within one field or one frame. A standby process is performed to secure

In step S7, after waiting for a predetermined time in the standby process, the measurement result Sig8 of the first brightness measurement circuit 8 and the measurement result Sig8 of the second brightness measurement circuit are obtained.
9 is read.

In step S8, the brightness E of the screen is determined based on the measurement results Sig8 and Sig9 by the following method.

That is, the following equation is used to calculate how much the control value of the current brightness adjustment falls between the threshold value determined to be bright and the threshold value determined to be dark.

W = 0 (when OUT> Tmax) W = (Tmax−OUT) ÷ (Tmax−Tmin)
(When Tmax ≧ OUT ≧ Tmin) W = 1 (When Tmin> OUT) Here, W is the ratio of the control value of the brightness adjustment immediately before the designation.
OUT is the control value immediately before designation. Tmax is a threshold value for determining that the image is bright. Tmin is a threshold value for determining that the image is dark.

The control value is a control value of an AGC value or an iris control value. The iris and AGC values are controlled continuously, so lower the AGC when bright,
When it is still bright, squeeze the iris.

On the other hand, when it is dark, the iris is opened, and when it is still dark, the AGC is raised. Therefore, Tmax, Tmin
Is the iris region, the control value is the iris control value, and if it is the AGC region, the control value is the AGC value control value.

Next, Sig9, which is the overall brightness, is multiplied by the calculated ratio W to obtain Sg9, which is the brightness of the designated portion.
The value added to ig8 is obtained as brightness E.

That is, E = Sig8 + W × Sig9 The brightness E is not simply the brightness of the designated portion, but
This is the brightness taking into account the brightness of the entire shooting range, and the brightness adjustment is controlled using this value.

The brightness E thus obtained is compared with a reference value REF in step S9. If the brightness E is equal, the brightness adjustment is terminated. If the brightness E is not equal, in step S10 the brightness adjustment is completed. The magnitude comparison between the brightness E and the reference value REF is performed.

In step S10, brightness E> reference value RE
If it is F, it is determined that it is brighter than the predetermined value, and step S11, which is a process of lowering the brightness, is performed.

At step S11, it is determined whether or not the current AGC value is larger than the minimum value. If the current AGC value is larger than the minimum value, at step S12, the AGC value is set to lower the brightness.
Decrease the value.

If the value is the minimum value, the AGC value cannot be reduced any more, so that the iris 2 is changed in the closing direction in step S13.

Thereafter, the process returns to step S6 again to wait for the change of the video signal and to measure the brightness again.

If it is determined in step S10 that the brightness E is smaller than the reference value REF, it is determined that the brightness is lower than a predetermined value, and the process of increasing brightness is performed in step S14.

In step S14, it is determined whether or not the current iris 2 is fully opened. If it is not fully opened, in step S15, the iris is opened to increase the brightness. If so, since the iris 2 cannot be opened any more, the brightness is increased by increasing the AGC value in step S16.

Thereafter, the process returns to step S6 again to wait for the change of the video signal and to measure the brightness again.

A series of data changes must be changed little by little because a sudden change will result in an unsightly image.

Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a block diagram of a portion related to brightness adjustment according to the second embodiment. The same components as those in FIG. 1 which is a block diagram of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. Omitted.

In FIG. 3, 5a is a variable gamma circuit, S
13 is a gamma control signal. FIG. 4 is a flowchart showing the procedure of the brightness adjustment method. FIG. 5 is a gamma characteristic diagram. Hereinafter, an outline of the operation will be described.

In FIG. 3, the luminance signal Sig7 generated by the signal processing circuit 5 is converted into the gamma characteristic set by the gamma circuit 5a, output to the next circuit (not shown) as Sig4, and measured for brightness. Input to the circuit 10.

In the brightness measuring circuit 10, the luminance signal Sig before entering the gamma circuit 5a generated by the signal processing circuit 5 is output.
From step 7, the brightness is measured.

The microcomputer 7 determines the correction value of the brightness from the measurement result Sig12 in the brightness measurement circuit 10, and uses the control signals Sig10, Sig11, Sig13 to control the iris 2, the AGC value of the CDS / AGC circuit 4, and the gamma circuit. 5a
Control.

The gamma characteristic to be set is, for example, a characteristic as shown in FIG. In FIG. 5, the characteristic of the normal standard setting Q and the characteristic of P which are varied so as to raise the low gradation and define the maximum value are selected, or the interval between them is varied.

FIG. 4 shows a flowchart of the above operation procedure. In step S20, it is determined whether or not a position on the screen at which the brightness is to be adjusted is designated.

Specifically, the XY input to the microcomputer 7
Is changed from the non-touched state to the touched state, and if the voltage is not touched, as step S21, an operation of correcting the voltage by the method described in the first conventional example is performed. On the other hand, if it is determined that the touch has been made, the microcomputer 7 obtains the XY coordinates from the input voltage Sig5 in step S22.

In step S23, a range for measuring brightness is determined from the obtained XY coordinates.

More specifically, a certain width is set with the designated point as the center. At this time, if the area is small, the influence of noise increases, so a certain area is required.

In step S24, the microcomputer 7 sets the determined measurement range in the brightness measurement circuit 10.

The brightness measuring circuit 10 measures the brightness of a designated range in one field or one frame. In step S25, a standby process is performed to secure time for the measurement.

In step S26, after waiting for a predetermined time in the standby process, the measurement result S
Read ig12.

In step S27, the brightness measurement result S
ig12 is compared with the reference value REF, and if they are equal, the adjustment of the brightness is terminated.
At 28, the brightness, the measurement result Sig12 and the reference value RE
A magnitude comparison with F is performed. In step S28, Sig
If 12> reference value REF, it is determined that it is brighter than the predetermined value, and step S29, which is a process of lowering the brightness, is performed.

At this time, if the brightness is reduced, the black portion other than the designated portion is further reduced in level, resulting in blackout, so that the gamma setting is increased.

First, in step S29, it is determined whether the gamma setting is smaller than the maximum value of the variable range. If the gamma setting is smaller than the maximum value, the gamma setting is increased in step S30.
If the gamma setting is at the maximum of the variable range, it cannot be increased any more, so it is not changed.

Next, it is determined in step S31 whether the AGC value is larger than the minimum value. If the AGC value is larger than the minimum value, in step S32, the AGC value is set to lower the brightness.
Decrease the value.

If it is at the minimum value, the AGC value cannot be reduced any more, so that the iris 2 is changed in the closing direction in step S33.

Thereafter, the process returns to step S25 again to wait for the change of the video signal and to measure the brightness again.

If Sig12 <reference value REF in step S28, it is determined that the image is darker than the predetermined value, and step S34 for increasing brightness is performed.

In step S34, it is determined whether the gamma setting is smaller than the maximum value of the variable range. If it is smaller than the maximum value, in step S35, the gamma setting is increased to increase the brightness, and the gamma setting is changed in the variable range. If it is at the maximum, you can't raise it any more, so don't change it.

Next, in step S36, it is determined whether or not the iris 2 is fully opened. If the iris 2 is not fully opened, the iris 2 is opened to increase the brightness in step S37, and the iris 2 is fully opened. In this case, since the iris 2 cannot be opened any more, in step S38,
Raise the brightness by increasing the AGC value.

Thereafter, the process returns to step S25 to wait for a change in the video signal and then re-measure the brightness.

[0103] These series of data changes require a little change because abrupt changes will result in unsightly images.

Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 7 is a flowchart showing the procedure of the brightness adjustment method. In step S40, it is determined whether there is a designation on the screen.

If not touched, step S4
As 1, an operation of correcting by the method described in the first conventional example is performed. On the other hand, when it is determined that a touch has been made,
In step S42, the gamma setting is changed from the standard value to the maximum value.

In step S43, XY coordinates are obtained from the input voltage Sig5. In step S44, the obtained XY coordinates are obtained.
After determining the range for measuring the brightness from the coordinates, the determined measurement range is set in the brightness measurement circuit 10 in step S45.

The brightness measuring circuit 10 measures the brightness of a designated range in one field or one frame, and the microcomputer 7 waits during that time in ST46.

In step S47, after waiting for a predetermined time, the result Sig12 measured by the brightness measurement circuit 10 is read.

In step S48, the read brightness data Sig12 is compared with the reference value REF. If the brightness data Sig12 is equal, the adjustment of brightness is terminated. If the brightness data Sig12 is not equal, in step S49, the brightness data Sig12 is compared with the brightness data Sig12. Reference value R
A magnitude comparison with EF is performed.

In step S49, Sig12> reference value R
If it is EF, it is determined that it is brighter than the predetermined value, and step S50, which is a process of lowering the brightness, is performed.

In step S50, it is determined whether or not the AGC value is larger than the minimum value. If the AGC value is larger than the minimum value, in step S51, the AGC value is reduced to lower the brightness.

If the minimum value is reached, the AGC value cannot be reduced any more, so that the iris 2 is changed in the closing direction in step S52.

Thereafter, the flow returns to step S46 again to wait for the change of the video signal and to measure the brightness again.

If Sig12 <reference value REF in step S49, it is determined that the image is darker than the predetermined value, and step S53 for increasing the brightness is performed.

In step S53, it is determined whether or not the iris 2 is fully opened. If the iris 2 is not fully opened, the iris 2 is opened to increase the brightness in step S54. Since the iris 2 cannot be opened, the brightness is increased by increasing the AGC value in step S55.

Thereafter, the flow returns to step S46 again to wait for the change of the video signal and to measure the brightness again.

When a series of these data changes is suddenly changed, the image becomes unsightly, and it is necessary to change the data little by little.

The difference between the conventional example and the third embodiment is whether or not the gamma is changed in step S42. The control of the iris 2 and the AGC value from step S46 to step S55 described below is the same as the conventional control. Is possible.

FIG. 6 is a block diagram in the case where the luminance signal for guiding the brightness to the brightness measurement circuit 10 and measuring the brightness is a signal that has passed through the gamma circuit 5a. Similar effects can be obtained by the flow of the third embodiment and the flow of the third embodiment.

Although the first embodiment has been described using two brightness measuring means, three or more measuring means may be used, for example, for normal control, for specified partial photometry, and for control value correction. Naturally, it is also possible to use a different method for photometry or, conversely, to perform a plurality of photometry in a time division manner with one brightness measuring means.

Further, although one brightness measuring means has been described as the second and third embodiments, a plurality of brightness measuring means may be provided and combined as described above.

[0122]

According to the first aspect of the present invention, a control value is calculated based on the output of the first measuring means and the output of the second measuring means, and the brightness of the video signal is adjusted with the calculated value. As a result, even if any position on the monitor screen is designated, balanced brightness adjustment can be performed.

According to the second aspect of the present invention, at least one or more brightness judgment reference values are set, and the brightness judgment reference value is compared with the output of the second measuring means immediately before the designation. If the output of the measuring means is determined to be bright, the brightness of the video signal is adjusted by the output of the first measuring means, and if it is determined to be dark, the first measurement is performed according to the degree of darkness. The output of the second measuring means is added to the output of the means at a specific rate, and the brightness of the video signal is adjusted by the calculated output. When a black subject is specified in a non-backlit state, the brightness is not increased more than necessary, so that an image with better visibility can be provided.

According to the third aspect of the present invention, no matter what position on the monitor screen is designated, the brightness adjusting means and the gamma characteristic varying means are appropriately adjusted according to the level of the designated portion. By controlling, overexposure and underexposure can be prevented.

According to the fourth aspect of the present invention, when the brightness is adjusted based on the part specified by the user at the time of photographing, the gamma characteristic variable means is fixed to another characteristic different from the normal control characteristic. By performing the brightness adjustment control in the state, the gamma is not included in the AE feedback loop, so that the brightness can be adjusted by a simpler method, and blackout or overexposure can be prevented.

According to the fifth aspect of the present invention, the designating means capable of designating a specific portion in a video signal is a touch panel laminated on a monitor, so that the state of a subject being photographed can be sequentially observed. The brightness can be adjusted immediately and accurately as needed.

[Brief description of the drawings]

FIG. 1 is a block diagram of a first embodiment of the present invention.

FIG. 2 is a flowchart of the first embodiment of the present invention.

FIG. 3 is a block diagram of a second embodiment of the present invention.

FIG. 4 is a flowchart of a second embodiment of the present invention.

FIG. 5 is a gamma characteristic diagram according to the second embodiment of the present invention.

FIG. 6 is a block diagram of another form of the second embodiment of the present invention.

FIG. 7 is a flowchart of a third embodiment of the present invention.

FIG. 8 is a block diagram of a first conventional example.

FIG. 9 is a measurement area diagram of the first conventional example.

FIG. 10 is a flowchart of the first conventional example.

FIG. 11 is a block diagram of a second conventional example.

FIG. 12 is a monitor diagram of a second conventional example.

FIG. 13 is a flowchart of a second conventional example.

[Explanation of symbols]

 Reference Signs List 1 lens 2 iris 3 CCD 4 CDS / AGC circuit 5 signal processing circuit 6 touch panel 7 microcomputer 8 brightness measurement circuit 9 brightness measurement circuit 10 brightness measurement circuit

Claims (5)

[Claims] 1. An image pickup apparatus having a monitor having a touch panel laminated on a screen, comprising: a brightness adjustment means for adjusting brightness of a video signal; a control means for controlling the brightness adjustment means; Specifying means for specifying a specific portion; first measuring means for measuring brightness from the video signal of the portion specified by the specifying means; and measuring brightness from the video signal when not specified by the specifying means At least one or more second measuring means, and calculating means for calculating a control value of the brightness adjusting means based on the first measuring means output and the second measuring means output. An image pickup apparatus for adjusting the brightness of a video signal using a control value obtained by the calculating means. 2. The computing means has at least one or more brightness judgment reference values, and a comparison between a control value by an output of the second measurement means immediately before designation and the brightness judgment reference value, When it is determined that the control value of the output of the second measuring means is brighter, the brightness of the video signal is adjusted by the output of the first measuring means. 2. The imaging apparatus according to claim 1, wherein an operation of adding the output of the second measuring means at a specific ratio to the output of the first measuring means is performed according to the degree. 3. An image pickup apparatus having a monitor in which a touch panel is laminated on a screen, comprising: a brightness adjusting means for adjusting the brightness of a video signal; a control means for controlling the brightness adjusting means; Designation means for designating a specific portion; brightness measurement means for varying a measurement area; gamma characteristic variation means for varying gamma characteristics; and computation for computing a control value of the brightness adjustment means based on the output of the measurement means. Means for adjusting the brightness of a video signal by controlling the brightness adjusting means and the gamma characteristic varying means based on the output of the designating means. 4. When a user designates a position during photographing, the characteristic of the gamma characteristic changing means is changed to a characteristic different from the characteristic when the position is not designated, and brightness adjustment control is performed. The imaging device according to claim 3, wherein: 5. The imaging device according to claim 1, wherein the designation unit that can designate a specific portion in the video signal is a touch panel stacked on a monitor.